Monday, April 20, 2026

A student-led experiment sets new limits in the search for axions

A study published in JCAP shows how, with limited resources and support from a large experiment, students built an axion detector and helped narrow down the properties of dark matter

Sissa Medialab

image:
The experimental apparatus built and used by students at the University of Hamburg
view more
Credit: Nabil Salama and Agit Akgümüs

In the era of precision cosmology, research often means big science: large observatories, highly complex instruments, international collaborations and substantial funding. Yet even in such an advanced field, progress is still possible — including in the search for elusive dark matter — through more agile approaches, driven by small teams and young researchers, supported by institutions and a good dose of ingenuity.

In a paper just published in the Journal of Cosmology and Astroparticle Physics (JCAP), a group of then-undergraduate students from the University of Hamburg built a cavity detector to search for axions — among the most promising candidates for dark matter — and set new experimental limits on their properties. The result was achieved with relatively limited resources, showing that even small-scale experiments can make a meaningful contribution to one of the most open challenges in modern physics.

Funding for students

The project was made possible through a student research grant provided by the University of Hamburg via the Hub for Crossdisciplinary Learning, which supports independent research initiatives.

“We were kind of embedded in the research group of the MADMAX dark matter experiment,” explains Nabil Salama, one of the authors of the study, currently pursuing an M.Sc. in Physics at the University of Hamburg. “MADMAX carries out a similar experiment on a much larger and more complex scale, and we benefited from their expertise and support.”
“We are very grateful for this help,” he adds, “and also to the University of Hamburg and the Quantum Universe Cluster of Excellence, which provided funding, access to key equipment such as the magnet, and invaluable support from researchers.”

Searching for dark matter

“The benefit of working with dark matter, or axions, is that we expect it to be present everywhere in our galaxy,” says Agit Akgümüs, first author of the study with Salama, currently pursuing an M.Sc. in Mathematical Physics at the University of Hamburg. “So essentially, no matter where you perform the experiment, you have some dark matter on your hand you can do experiments with.”

The funding was first used to build the experimental setup, starting with a resonant cavity made from highly conductive materials, along with the necessary electronics, cabling, supports and measurement instruments. “The detector we built is essentially the simplest version of a cavity detector for dark matter,” says Salama.
The team did not work entirely from scratch: in addition to the funding, they relied on existing infrastructure and equipment provided by the university and collaborating research groups.
The experiment was then tested, calibrated and operated to collect data for analysis.

“We reduced very complex experiments to their essential components,” says Salama. “The result is a less sensitive setup, limited to a small search window, but still capable of producing new scientific data.”

No signal found, new limits set

“The search for axions involves exploring a wide range of possible parameters,” adds Akgümüs. “Our experiment covers only a small region, with limited sensitivity, but it still helps narrow down the possibilities. To actually find the particle, we need either much larger experiments or many different ones, each probing a specific region.”
At the end of the data-taking phase, the team did not observe any signal attributable to axions. Rather than a failure, this is a meaningful scientific result: it allows researchers to exclude the presence of axions with certain properties within the explored mass range, particularly those with stronger interactions with photons. In this way, the study helps narrow the parameter space and guide future searches.

“I think the point of our experiment is that things can be done on a smaller scale,” says Salama. Akgümüs adds: “Our results are naturally more limited than those of larger experiments. Performance scales with resources and complexity. However, we have shown that it is possible to reduce these setups to a much smaller scale — even to projects developed almost independently by students — while still producing real scientific data.”

During the peer-review process of the paper, a referee made a particularly notable comment, Salama recalls. According to the referee, once the axion is discovered and its properties — especially its mass — are known, experiments of this kind could become far more accessible, potentially even suitable for teaching laboratories. “We were told that setups like ours could one day become standard student lab experiments,” says Salama. “In a way, we may have anticipated that future, showing that it is already possible to build and operate such an experiment on a small scale.”

The paper “A New Limit for Axion Dark Matter with SPACE” by M. A. Akgümüs, N. Salama, J. Egge, E. Garutti, M. Maroudas, L. H. Nguyen, and D. Leppla-Weber has been published in the Journal of Cosmology and Astroparticle Physics (JCAP).

Salama (left) and Akgümüs (right) with the experimental apparatus

Credit

Nabil Salama and Agit Akgümüs

Journal

Journal of Cosmology and Astroparticle Physics

Method of Research

Experimental study

Article Title

A new Limit for Axion Dark Matter with SPACE

“Can we hear lost voices again?” Restoring ‘my voice’ by reading light and reviving with AI

Pohang University of Science & Technology (POSTECH)

image:
Schematic diagram illustrating the difference between communication using conventional voice-based methods and the developed silent speech interface.

view more
Credit: POSTECH

Hearing words even when spoken in silence—a new technology has been developed that reads the subtle movements of neck muscles using light and employs AI to restore them into actual voices.

A research team led by Professor Sung-Min Park (Department of IT Convergence Engineering, Mechanical Engineering, Electrical Engineering, and the Graduate School of Convergence) and Dr. Sunguk Hong (Department of Mechanical Engineering) at POSTECH (Pohang University of Science and Technology) conducted this study. The findings were published in the online edition of Cyborg and Bionic Systems, a Science Partner Journal in the field of biomedical engineering.

The research began with tiny changes that occur around the neck when a person speaks. It is not just the vocal cords that create sound. Whenever we speak, the muscles and skin around the neck move together, drawing an invisible "movement map" on the skin. The research team focused on the fact that these microscopic movements contain information about what the person intends to say.

To capture this information, the research team developed a ‘Multiaxial Strain Mapping Sensor.’ This sensor, which combines a miniature camera with small reference markers on a soft silicone material, can be conveniently worn on the neck and detects even the most minute skin movements. The wearing position and tightness can be adjusted for the individual, and an algorithm automatically corrects errors that may occur when the device is reattached, allowing it to operate stably in daily environments.

The strain patterns collected by the sensor are analyzed by AI. It estimates the words or sentences the user intends to say and combines them with voice synthesis technology trained on the individual's vocal characteristics to reproduce the actual voice. Even without producing sound, it "reads" the speech and converts it into a voice.

Existing voice restoration technologies used biological signals such as ‘EMG (electromyography)’ or ‘EEG (electroencephalography),’ but they had limitations in daily life due to complex equipment and uncomfortable wearability. The research team solved this problem with a wearable sensor and confirmed through experiments that speech could be reconstructed with high accuracy even in noisy environments such as factories.

The scope of application is also broad. It is expected to be used in various fields, such as communication assistance for patients who have lost their voices due to vocal cord diseases or laryngeal surgery, communication technology for industrial sites without microphones or radios, and even "silent communication" in libraries or conference rooms.

Professor Sung-Min Park, who led the study, said, "We hope this technology will accelerate the day when patients with speech disorders can reclaim their voices," adding, "It is a noteworthy technology because it has a wide range of potential applications, including assisting laryngectomized patients, communicating in noisy industrial environments, and even supporting silent conversations.“

Meanwhile, this research was conducted with support from Doctoral Course Research Grant Program and the Mid-career Researcher Program of the Ministry of Education, Bio&Medical Technology Development Program and the Pioneering Convergence Science and Technology Development Program of the Ministry of Science and ICT.

Journal

Cyborg and Bionic Systems

DOI

10.34133/cbsystems.0536

Article Title

Soft Multiaxial Strain Mapping Interface with AI-Driven Decoding for Silent Speech in Noise

E-cigarette devices expose users to toxic metals, UTS study finds

University of Technology Sydney

Vaping is largely believed to be a safer alternative to cigarettes, but new research shows that vaping devices can deliver toxic metals directly into lung tissue.

A study published in Analytical and Bioanalytical Chemistry by University of Technology Sydney (UTS) researchers showed that even short‑term vaping at exposure levels below typical daily human use resulted in measurable accumulation of toxic metals in lung tissue – including lead, copper and nickel.

Lead researcher Dr Dayanne Bordin, a lecturer in analytical chemistry, said the pre-clinical study provides the first evidence that e-cigarette aerosols include metal-containing (organometallic) species, including those associated with tin and mercury – forms that are often more bioavailable and biologically reactive than inorganic metals.

“From a risk perspective, the findings reveal under‑recognised hazards associated with vaping,” she said. “Metal emissions and their biological effects are rarely incorporated into current safety assessments or public understanding. Unlike cigarettes, which are a relatively consistent products, e-cigarettes and devices are often manufactured with poor quality control involving materials and components with unknown toxicological relevance.

“The metal profiles observed are consistent with emissions from heating coils and electrical components, identifying the device itself as a critical source of exposure and highlighting important gaps in how vaping risks are evaluated.”

Dr Bordin explains this is important because many people believe vaping carries less risk than conventional cigarettes. This perceived reduction in harm, along with misleading marketing campaigns, has contributed to the rapid uptake of e-cigarettes globally, particularly among younger demographics. In Australia, for example, e-cigarette use among young adults increased from 5.3% in 2019 to over 21% in 2023, with a similar rise in adolescents.

“Our findings challenge the assumption that e-cigarettes are safer and shows how critical it is to review current vaping regulations, which should be expanded to include device-derived emissions, not just e-liquid composition,” she said.

“Vaping can deliver toxic metals directly into the lungs, even after short-term use. This information is important for anyone considering vaping, especially young people, because these metal exposures are largely invisible and rarely discussed.

“Specifically, there is a need for standards and routine testing of metal and organometallic emissions from e-cigarettes, particularly from heating coils and internal components,” said Dr Bordin.

“The results also support updating risk assessment frameworks and public health guidance to incorporate metal exposure and bioaccumulation and improving consumer awareness around these previously unrecognised risks.”

Journal

Analytical and Bioanalytical Chemistry

DOI

10.1007/s00216-026-06487-1

Method of Research

Observational study

Subject of Research

Animals

Article Title

Analytical investigation of metal distribution from e-cigarette aerosols to lung deposition using multi-platform mass spectrometry

Article Publication Date

16-Apr-2026

Hong Kong’s waters at risk from over-the-counter (OTC) drug pollution

KeAi Communications Co., Ltd.

image:
A novel holistic paradigm for effective control of priority pharmaceuticals in complex river-estuary continuums.
view more
Credit: City University of Hong Kong

A recent study of Hong Kong's river and estuary systems has uncovered an overlooked major source of water pollution: common over-the-counter (OTC) drugs. Researchers from City University of Hong Kong (CityUHK) found that accessible, everyday OTC drugs, such as painkillers, antihistamines, and caffeine, accounted for up to 85% of pharmaceutical pollution in these waters during the wet season—far outpacing prescription-only medicines.

The study was led by Professor Kenneth Mei-Yee Leung, Director of the State Key Laboratory of Marine Environmental Health (SKLMEH), Chair Professor of Environmental Toxicology and Chemistry, and Associate Dean of Science College at CityUHK, in collaboration with the Guangdong Research Institute of Water Resources and Hydropower at Guangzhou in China.

"We often assume that complex or restricted prescription medications pose the greatest environmental risk, but our findings shine a new light on everyday household medicines," says Professor Kenneth Leung. "Because OTC drugs are easily accessible and continuously consumed, they act as 'pseudo-persistent' pollutants. Even if they break down easily, our constant use means they are always present in our aquatic ecosystems."

Pharmaceuticals tend to be mobile in water due to their molecular properties, allowing them to transport through river networks and enter the ocean via estuaries, posing further threats to marine ecosystems. In fact, it is well known that pharmaceuticals are present in rivers, estuaries, and coastal waters worldwide.

"Pharmaceutical pollution is not a local pollution issue at a specific site. Hence, we should adopt a river-estuary-sea perspective to prioritize pollutants for control and management," Leung adds.

Notably, existing site-specific risk assessments lack a macroscopic perspective, making it difficult to distinguish widespread ecological threats from localized contamination. To address this concern, the research team introduced a newly developed paradigm that could advance the risk assessment.

"Our approach integrates the river/estuary-to-sea transport trajectory modeling with consideration of persistence, mobility, and toxicity (PMT) of the pharmaceutical pollutant and thus the results can better evaluate and prioritize pharmaceuticals for risk management," explains Leung.

They team found that 80% of the investigated pharmaceuticals met the criteria for being PMT pollutants in water environments. Caffeine, paracetamol, cetirizine, cimetidine, sitagliptin, and fexofenadine were identified as priority pollutants for control in the river-estuary system of Hong Kong, exhibiting a greater potential to harm sensitive marine habitats of the endangered Indo-Pacific humpback dolphin. Among those, the top four pharmaceuticals with the highest risks were all OTC drugs.

By pinpointing high-priority pharmaceuticals and the rivers that contribute most to their spread, the team suggests that targeted interventions, such as upgrading sewage treatment and installing stormwater retention tanks along major discharge rivers, could effectively reduce their emissions into the sea.

"Raising public awareness is also essential," says Leung. "Residents should return unwanted or expired medications for proper disposal rather than throwing them away or flushing them. Clearer government guidance on safe drug disposal is urgently needed."

Measurement of water quality parameters

Water sampling from Shing Mun River, Hong Kong